Safety belt



Jan. 8, 1952 c. w. ROSE A2,581,772

SAFETY BVELT C. W. ROSE SAFETY BELT Jan. s, 1952 2 SHEETS-SHEET 2 FiledOct. 4, 1946 Patented Jan. 8, 1952 Y SAFETY BELT Clarence W'. Rose,Denver, Colo., assignor to Rose Manufacturing Company, Denver, Colo., apartnership Application October 4, 1946, Serial No. 701,366

(Cl. .2N-49) 3. Claims.

- 1 This invention relates to safety devices of the class used to checkthe falling of workers or others wearing the device and particularly tosafety belts having a double reach of rope, one

1 being a service rope and the other beingfasafety or'reserve rope,terminals, adaptedl for anchorage,

-being engaged to the endsv of such ropes.:

ythe present specification will be in termsY of such embodiment, but itwill be understood that there are other uses and embodiments of theinvention which will readily occur to those skilled in the art and I amnot to be limited to the embodiment or' use in the terms of which thisspecification'is written. e

An object of the present invention is to so conf struct a safety beltvthat a stretchable rope may be used as the safety rope and 'fulladvantage be taken of the qualities of such rope while aifording meansfor meeting the other requirements of such belt for the efficient usethereof.

A further object is to provide, in such a belt, the combination of astretchable safety rope, a substantially non-stretchable.` service ropeand means for automatically-disengaging the service ropefrom a terminalupon the occurrence of'predetermined conditions,

A further object 'isl to provide a belt which, in case of the accidentalfall of the wearer, will retard the fall and ease the wearer to a stopwhile providing forv the free and unobstructed use of the belt undernormal working conditions. f

Still furtherobjects of the invention are to provide, in such a belt,simple and `easily operable means for adjusting the length lof theservice rope and for preventing the twisting of the service rope aroundthe safety rope which tends to result from the tension on the servicerope in use and to provide thesafety features, above ,'mentioned andhereinafter described, while reducing-the number of yparts in Aand theweight of belts of thisclass as heretoforev constructed and assembledvin efforts to accomplish similar results.

A still further object is to provide a suitable 2 and novel means ofprotecting and preserving the safety rope.

With these and other objects in view, .all of which will more fullyhereinafter appear, :the invention comprises certain novelconstructions, arrangements and combinations of parts as will now bedescribed and claimed and as illustrated. in preferred embodiment, inthe accompanying drawing in which:

Fig. l is a perspective view of a safety belt for window cleaners, withits usual accompanying appliances but with the front including fasteningmeans cut away, embodying the present invention. i

Fig. 2 is an elevation of a fragment of the safety rope of the typeadapted for use in the present invention illustrating a. coveringadaptable for use on a rope performing its proper functions as a part ofthe present invention.

Fig. v3 is a section taken on line 3--3 of Fig. 2.

Fig. 4 is a view illustrating the belt, service rope, safety rope andassociated parts in the positions assumed by said parts when a workman,wearing the belt, has fallen, with only one terminal anchored, and hasnearly reached the end of the service rope. f

Fig. 5 is a view like Fig. 4 but illustrating the position of the partsimmediately after the service rope has been disconnected by the force ofthe fall of the workman and the safety rope is elongating, exerting adecelerating force.

Fig. 6 is a view like Fig. 5 but showing the position of the variousparts when the decelerating force of the safety rope has brought theWorkman to a gradual stop.

Fig. 'l is a detail view of a terminal and frag.- ments of the safetykrope and of the service rope and the link normally connecting saidservice rope with the terminal, which also constitute adjustment meansfor the servicerope.

Fig. 8 is a View similar to Fig. 7 but illustrating the link after itsopening and the disconnection of the servi-ce rope fromthe terminal hereillustrated as a release of the rope by the link.

Fig. 9 is a side elevation of one of the duplex rope eyes.

In the present embodiment of this invention IA provide a strapor belt ll of canvas webbing or other suitable material, the ends of which,including the buckle or other fastening means, may be of any suitableconstruction and are no part of the present invention and are,therefore, not illustrated.

The member Il, which will be referred to as the strap in distinctionfrom the whole assembly which is V'called a "safety belt, is providedwith a suitable back pad I2. The pad I2 carries a protector I3, securedto the pad along its upper and lower edges by sewing or other suitablemeans indicated at I3a, whereby strap II may be passed between the padand the protector, thus furnishing a secure engagement of the strap withthe pad but permitting a sliding of one relative to the other.

Pad I2 carries ropes eyes I4 shown in detail at Fig. 9 and comprising abase Ida adapted for being secured to the pad, a slot Ib for strap IIand eyes Hic and Idd for the service and safety ropesV respectively. Thebase I4a may be z secured to the pad by any suitable means, not

` vsubstantially non-stretchable material, lies-slid- .ably within theeyes Ille.

The safety rope I6, ofV stretchable'material and more particularlyhereinafter described, lies slidably Within the 'eyes Idd. Terminals I1,of any construction suitable for anchoring engagement with anchorsprovided on or near the window frames of buildings, are carried at theends of the ropes as will now be described. V; v Each end of the servicerope I5 is tied to link' I8 engaged to the terminal. The link'is notsolid but its ends Isa are brought together, 'as clearly shown at Fig.l, making a closed link which links the service rope to the terminal butwhich will open and release the rope when subjected to a suiicient andpredetermined pull. 'Ihe link is of such material and size that it willwithstand, without opening, the pulls or lstresses that will be exertedVupon it during and by the normal and intended activitiesl of the!wearer of the belt. The link is, however, so constructed that it willopen and release the service -rope when subjected to the pull of thebody of the wearer falling, as illustrated at Fig. 8.

Safety rope I6 is securedto the terminals at both itsV ends by suitablemeans as by looping the end through the terminal and binding the end tothe reach of the rope as illustrated at The ends of the service rope maybe tied to the link in any desired manner but to facilitate adjustmentsvof thel rope as to length it is desirable to use a slide 'hitch asillustrated most clearly at Fig. 7," whereby tension on the mainuntwist, resulting in a looping or kinking if the lrope is permanentlyfastened at both ends.

In such cases a swivel is commonly inserted in the rope to allow for`such untwisting. The necessity for a swivel or other such means isobviated,

in the present case, by the slip hitch connec- .shock absorbingqualities.

tion of the rope to the link, it being a matter of only a moment toloosen the hitch, straighten the rope and again tighten the hitch. Infact such operation will generally be unnecessary because thestraightening will automatically occur during the ordinary adjustmentsof length of the rope.

'I'he safety rope must function as a shock absorber by virtue of eitherqualities inherent in the rope or equipment incorporated therein or'associated therewith. The structure and functionof the service rope andits associated parts will be the same in either case. There are,however, decided advantages in using a safety rope f' which has theshock absorbing qualities inherent within it and the use of such a ropeis a part of the present invention, and it is illustrated at Figs.'2 and3, where the rope having the shock absorbing qualities is indicated atI9 and a suitable covering for such rope is indicated at 2, the coveringonly being visible at vweight *whenl the stretching limit is reached.

Certain nylon rope now on the market has these qualities and such ropecan be used as the safety rope in the preferred embodiment ofthisinvention. f

Any wear on such nylon or other similar rope would affect -both itsstrength and its resistance to stretching and would therefore change itsAccordingly,` it is necessary to guard against the wearing of the safetyrope from any cause, for example, by the rope eyes I4, protector I3, oranything else vwith which the rope may have contact. This protection maybe accomplished by vwinding rope. I9 with a small rope or twine 20 whichwill cover .rope I.9 completely and smoothly so long as the rope remainsin normal, unstretched condition and will thus protect it from wear andother deteriorating influences. Moreover, when the winding 20 wears andbecomes frayed its appearance .gives warning, before anywear of the ropeI9 ens outor is readily broken by the stretching. The breaking ofthewinding is not Yobjectionable because a second use of a rope which hasonce saved aworker, is not contemplated. Other coverings may be used forrope I 9.

The details of operation of the rbelt under all Aconditions is notattempted to be described, or

illustrated. One typical and most frequently occurring and mostdangerous case is sufficient for illustration. That is the case shown inthe draw- .ing in which a window washer falls' whenonly lone terminal isanchored to the window casing or adjacent wall indicated at X in Figs;4, 5 and-6. In such a case the wearer of the belt drops-to the 'positiondiagrammatically illustrated at Figi-4 'at which point the service ropehas slid through the rope eyes and one of the rope eyes has con"-`tacted the'assembly of parts at the unanchored :assigns 'terminal andthe falling bodyi'sexertingfitsfull `falling impact upon thatv assemblyand thus' exerting its full downward pull on the service ricpe v. whichis about-torcause-a separation of the link with resulting release of theend of the service rope which is linked to the anchored terminal. lAfter. falling this distancel the.v impact ofthe falling man against thelower end of. the service rope will,l when measured. in weight, be muchmore than the weight'of` the man, and were the service-- rope and itslink attachment to the'. anchored terminalstrong enoughk to withstandsuch. impact, it might Vresult inieither serious injury to thel man-fromsuch` a. sudden stop'. or'in pulling out forl breaking the anchorage`and letting the man drop to the. ground.

the shockA absorbing degree of the safety rope,

-actual conditionsV encountered in daily work Some are so weak that nobelt could be devised which would prevent such anchorage being pulledout by the falling of a worker for any substantial distance. Others arestrongly enough installed to withstand almost any pull exerted by afalling worker, while a great many anchorages are strongly enoughinstalled to withstand a pull considerably more than the weight of theman but not to withstand the pull of that weight plus the added pullresulting from his falling a substantial distance. For these 'reasonsinorder as far as possible to prevent the pulling out or breaking of theanchorage as well as to avoid injury to the worker by too sudden a stop,the safety rope should be so adjusted or constructed that it will keepthe pull on that rope (during the deceleration period) as low aspossible and still-- decelerate the fall of the belt wearer to a stop ata substantial distance before the end of the lol cliored'; andv bothlinks are operativefandV the "pull is* equalized between them so thatthe two links, eachcapabl'e of holding a two hundred fifty pound pullwithout opening, wouldwithstand a five hundredpound pull on the servicerope without-either link; opening. The foregoing Afigures are notintended as definition or limitation but are assumed simply for thepurpose of illustrating the problem to `be met in coordinating thedegree and quality of stretchablenessL of the safety rope and thepull-withstanding strength of the link.

Returning to the drawing and theV operation .'Iny coordinating thestrength' of the' link and therein illustrated, Fig. 5 diagrammaticallyAil-l lustrates the` situation and position of the various elements incase of a falland immediately after thev linkV hasv been opened by thepull on theA service rope-and'has released the service rope, therebylimmediately transferring thel pull exerted by the falling body from theservice-1 rope to thev safety'rope which now begins to stretch under thepull of the falling body, but which also begins to exert a retardinginfluence on such body.

Suppose the man Weighs one hundred fty pounds and the rope is adapted tostretch in response to any pull over three hundred pounds.

The impact of the body which, in effect, drops from the service ropeonto the safety rope, will, because of its momentum, exceed threehundred pounds in pull on the safety rope, and that rope will stretchand continue to do so as long as the pull exerted by the falling body isover three hundred pounds but the resistance of the rope will deceleratethe speed of the falling body until it has reduced the pull to threehundred pounds and there stopped the fall because the rope will notfurther stretch after the pull has been reduced to that amount. Theposition of the variv ous parts when the body has come to a stop issafety rope is reached or, in case of the stretchi y.

able rope, before the limit of stretch is reached.

For example, the stretcnable rope above re-l ferred to, will stretch 400per cent, i. e. to a total of ve times its unstretched length. Such arope i having a normal length of eight feet will stretch to sodecelerate the fall of a man, wearing such f a belt, that he will bebrought to a stop when illustrated at Fig. 6.

The stretching of the safety rope in the manner v hereinbefore describedis actually a drawing action, physically similar to the common drawingof a wire wherein there is a stretching accompanied by permanentelongation. The word drawing more exactly describes the action than theword stretching heretofore used. The energy required to cause suchdrawing in the safety rope results in the gradual deceleration of afalling man, and the essential physical characteristic of the safetyrope is that it be of drawv able material initially in an undrawn state,such as undrawn nylon, and that as a result of the drawing the rope ispermanently elongated to a the rope is about twenty-four feet and not toexceed about thirty-two feet in length.

Now assume that such a .deceleration will result in a three hundredpound pull on the anlength substantially greater than the undrawn lengthand of a substantially less diameter than the undrawn rope but withoutany loss of strength of the rope.

chorage, the strength of the link should be such that it will open witha somewhat less pull than the pull expected'to be exerted on the safetyrope" 7' after the service rope has been released by sepan' ration ofthe link. Where such expected pull von the safety rope is three hundredpounds, the

link could be made so as to open responsive to,

say, a two hundred fifty pound pull, in which rope. Using the aboveillustrative gures as a further example, a link which will remain closedup to a two hundred fty pound pull will be of While I have illustratedand described many details of construction there are many alternativeand equivalent structures which will occur to those skilled in the artand which are within the scope and spirit of my invention and of theappended claims, and I am not to be restricted in my protection to thedetails here illustrated or described.

I claim:

l. A safety device including a belt, means carried by the belt havingeyes for slidably securing ropes to the belt, a substantiallynon-stretchample strength to take vcare of all conceivable f 1 pullswhich could be exerted by the normal acsuch normal activities, bothterminals are an'- able service rope secured by some of said eyes, a Ysafety rope of drawable material in an undrawn state, secured by otherof said eyes, said undrawn drawable material being of a character whichcan tivities of the user of the belt because, during age terminals atthe ends of said ropes,-and a link engaging an end of the service ropeto a terminal, said link being adapted vtosever and repull as caused'bythe fall .of the Wearer'of the belt, said safety rope being directlysecured to said terminal.

2. In a device as .defined in claim 1, the link for attaching theservice rope to the terminals having a weakened portion.

3. A safety device including a belt, means carried by the belt havingeyes for slidably securing ropes to the belt, a substantiallynon-stretchable service rope secured by some of said eyes, a safety ropeof undrawn nylon secured by other of said eyes, anchorage terminals atthe ends of said adapted to sever and release the service roperesponsive to a predetermined pull as caused by the weight ofa--Wearerof the belt 'in a-fall, said safety rope being directly secured to theterminals. Y l

CLARENCE W. ROSE.

. l REFERENCES CITED The following references are of record in theflleof this 'patent-,11' 4 Y UNITED STATES PATENTS Number Name Y Dat'e341,219 Y' Cadbury et al. -May 4, 1886 2,130,948 Carothers Y Sept;:20,1938 2,175,571 Y "Rose et al. Oct. 10, 1939 2,302,642 Deike, Jr.' Nov.17, 1942 2,313,058 Francis, Jr. Mar. 9, -1943 2,317,346 Reith -VApr. 27,1943 2,343,892 Dodge et al. Mar. 14, 1944 2,433,722 Weiss Dec. 30, 1947

